Buttonhole-cutting mechanism



E. B. ALLENJ BUTTONHOLBCUTTINGMECHANISM.

RPPLICATION FILED APR. 30. 1920.

Patented June 7, 1921.

4 SHEETS-SHEETI iNVENTOR ATTORNEY WITNESSES:

E. B. ALLE-N. BUTTONHOLE CUTTING MECHANISM.

APPLlCATlON FILED APR. 30, 1920.

Patnted J ne 7, 1921.

ATTORNEY INVENTOR 4 SHEETS-SHEET 2.

E. B! ALLEN. BUTTONHOLE CUTTING MECHANISM. I APPLICATION FILED APR. 30. 1920.' 1,880,340, Patented June 7, 1921.

4 SHEETS-SHEET 3- WITNESSES: i a? INVENTZ R;

ATTORNEY E. B. ALLEN. BUTTONHOLE CUTTING MECHANISM.

APPLICATION FILED APR. 30. 1920.

PatntedJune 7, 1921.

4 SHEETS-SHEET 4.

. V I E1- WITNESSES:

INVENTOR ATTORNEY UNITED STATES PATENT OFFICE.

EDWARDB. ALLEN, OF NEW TOWN, CONNECTICUT, ASfiIGNOB TO THE SINGER MANU- FACTURING COMPANY, OF ELIZABETH, JERSEY, A CORPORATION OF NEW JERSEY.

BUTTONHOLE-CUTTING MECHANISM.

To all to 710% it may concern Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Newtown, in the county of 1? airfield and State of Connecticut, have invented certain new andeuseful Improvements in Buttonhole-Cutting Mechanism, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to buttonhole sewing machines and more particularly to but "tonhole cutting mechanism of the punch- .a-nd-d1e type adapted for use in such matain specified defects of prior machines,

chief among which defects is the inability of the machine to produce a buttonhole with uniformly spaced over-edge stitches covering the sharp upper corner of the work adjacentthe punched out buttonhole slit and the lack of efiicient means for removing from the field of operations the clippings or sections of material which are cut out to form the buttonhole, so that said clipbuttonhole sewing.

A further object of the invention is to provide an eyelet-end buttonhole cutter of the pivoted punch and apertured die type Specification of Letters Patent.

- prior machine.

Patented J line 7, 1921.

Application filed April 80, 1820. Serial No. 377,850.

which is of sturdy construction and which can be manufactured at low cost.

A further object of the invention is to provide improved means for securing the punch element to its carrier, to the end that the punch element may, regardless of its cross-sectional shape, be readily removed from and replaced in operative position, and adjusted relative to the stitch-forming mechanism.

in the particular embodiment of the invention chosen for the purposes of the present disclosure, the work-holder is adapted to be moved rearwardly from stitching position to meet the advancing buttonholecutter; the object being to cut the buttonhole at a position intermediate the stitching position and the retracted or normally ineffective position of the buttonhole'cutter. In my Patent No. 1,330,156, of February 10, 1920, I have disclosed mechanism for disconnecting the work-holder from the feed-wheel and shifting it rearwardly to meet the advancingcutter. A further object of the present invention is to provide a more rigid form of such mechanism; one less likely to show the ill effects of lost motion after long continued use.

Further objects of the invention will appear from the following description and claims. n

F or the purposes of the present disclosure the invention is embodied in a buttonhole sewing machine constructed substantially in accordance with the disclosure of my said copending application Serial No. 367,297 except as to such features as may hereinafter be particularly referred to as distinguishing the present machine from my said The present machine embodies a pivoted cutter-lever disposed -mainly above the level of the work-support and carrying a solid punch-element adapted to enter a hollow die-element stationed below the work. In the present machine, the solid punch-element is in the form of a thin blade having the shape of an eyelet-end buttonhole slit in cross-section and curved edgewise substantially concentrically with the pivot of its carrier lever; the thickened and rounded edge which cuts the eyeletend of the slit being nearer the pivot of the carrier-lever than the opposite edge.

The punch-element is preferably clamped in a carrier comprising a pair of blocks held together by screws. These blocks are formed in their meeting faces with curved grooves complementary to the side surfaces of the punch-element, so that the punchelement may be accurately seated and securely clamped between said blocks. The

carrier-lever is preferably formed at its forward end with a seat to receive and accurately locatethe punch-carrier relative to the pivot of the carrier-lever, while permitting sidewise adjustments in directions parallel with the axis of said pivot.

The die-element is formed with an aperture complementary to the punch-element and, in the embodiment of the invention illustrated, is adjustably mounted upon a tailed description taken in connection with the accompanying drawings in which Figure 1 is a side elevation of the buttonhole cutting mechanism of the machine with the parts in the respective positions which they occupy before the machine is started. Fig.

' 2 is a similar view at the period of the cycle when th buttonhole cutting elements are closed upon the work. Fig. 3 is a horizontal section through the bracket-arm standard of the machine at a level above the base; the workrholder being removed. Fig. 4 is a fragmentary side elevation, partly in section, of the buttonhole cutting elements and their supporting levers. Fig. 5 is a reverse side-elevation of the parts shown in Fig. 4. Fig. 6 is a top plan view of the front endportion of the upper cutter-lever. Fig. 7 is a plan view of the die-element as mounted upon its carrier-lever. Fig. 8 is a disassembled perspective view of the punch element and its split carrier block. Fig. 9 is a cross-section of the punch element as shown in Fig. 8. Fig. 10 is a front elevation of the parts shown in Fig. 4. Fig. 11 is a section on the line 11-11, Fig. 4. Fig. 12 is a fragmenting transverse vertical section through the machine, looking toward the standard. Fig. 13 is a perspective view of the coupling element and associated parts .which connect the work-holder with the feed-wheel. Fig.14 is a bottom plan view of the parts shown in Fig. 13. Fig. 15 is an elevation, partly in section, of the mechanism for uncoupling the work-holder from the feed-wheel and shifting the work-holder to cutting position; the parts being in sewing position. Fig; 16 is a similar view of the parts after the cutter shaft has executed the first quarter of a revolution preparatory .to cutting a buttonhole slit.

For the purposes of the present disclosure, the invention is described as embodied in a machine constructed substantially in accordance with the disclosure of my said c0- pending application Serial No. 367,297, with the exception that the work-holder is provided with mechanism similar to that disclosed in my Patent No. 1,380,156 for shifting it rearwardly from stitching to cutting position substantially simultaneously with the advance of the cutter-levers. The frame of the machine comprises the usual bed 1 and bracket-arm standard 2 in which is ournaled the cutter-shaft 3 which is actuated intermittently from the constantly rotating pulley 4 through the well known one-rotation controlling clutch 5. In the present instance, the cutter shaft 3 carries a cutter advancing cam 6 and cutter-actuating cams 7 and 8, of the closed type. The cams 7 and 8 are formed in their adjacent side faces with the respective grooves 7, 8 which are entered by the respective follower rolls 9, 10 mounted upon the respective auxiliary cutter-levers 11, 12 pivoted at their rearward ends upon the stationary pin 13 which is carried the framelug 14.

At their forward ends, the auxiliary cutter-levers 11, 12 are slotted longitudinally at 15, 16 respectively, for reception of the lateral rolles 17, 18 mounted respectively upon the rearward ends of the main cutterlevers 19, 20 which are pivotally supported at 21 upon the traveling fulcrum-block 22 V whichis shifted toward and away. from cutting position by means of the usual linkconnection 23 with the cam 6.

The upper cutter-lever 19 is cut away or recessed at its forward end to form the walls 24, 25 which are disposed in planes at right angles to one another and parallel with the axis of the fulcrum-pin 21. The walls 24, 25 form a seat for the reception of a punchcarrier comprising the separable blocks 26, 27 which are adapted to be clamped upon the solid punch-element 28 by means of the screws 29. In the present embodiment of the invention, the punch-element 28 is in the form of a thin blade curved'edgewise concentrically with the fulcrum-pin 21 of its carrier-lever. One edge 30 of the blade is enlarged and rounded to correspond in shape with the eyelet-end of the buttonholeslit to be punched. The punch-element 28, as shown in crossseetion Fig. 9, is shaped to correspond with the eyelet-end buttonhole slit which it is desired to cut.

The clamping block 26 is formedwith a rier-lever.

curved groove 31 complementary to the punch-element 28, so that .said punch-element may, in effect, be embedded in the block 26 to an extent nearly equal to the thickness of the thinner portion of the blade 28. The block 27 is formedwith a curved groove 32 to receive only the thicker edge-portion 30 of the punch-element. These grooves, being concentric with the axis of the carrier lever 19, permit the punch-element 28 to be adjusted endwise in the.curved path of its operative movement without shifting it out of register with the die-element.

- The block 26 is tapped at 33 to receive the screw-bolt 34 which serves to secure the punch-carrier tightly in engagement with the walls 24, 25 of its seat in the upper car- The bolt 34 passes through an enlarged aperture 35 in the upper cutterlever 19, thus permitting lateral adjustment of the punch-carrier 26, 27 relative to the cutter-lever 19. It will be seen that by providing a split carrier-block having opposed grooves complementary to the contour of the punch-element and curved concentrically withthe pivot of the punch-carrying lever, a construction is provided which is independent of the particular cross-sectional shape of the punch-element and which will permitready removal of the punch-element from and replacement in its holder, and adjustment of the punch-element relative to the stitch-forming mechanism.

The die-element 36 is formed with an aperture 37 to receive the punch-element 28 during its cutting stroke. The die-element is also formed in rear of the aperture 37 with enlarged apertures 39 for the screws 40 which secure the die-element to the flat seat 41 formed on the lower cutter-lever 20. The enlarged apertures 39 permit adjustment of the die-element laterally of its supporting lever, so that it may be located with precision to receivethe punch-element. The forwardend-portion of the die-element is held upon the seat 41 by means of the gib 42.

In practice, the punch-element 28 is ad justed in its carrier 26, 27 so that it projects sufliciently below said carrier to fully enter the die-element when the cutter-levers are closed. The carrier 26, 27 is next adjusted laterally in its seat 24, 25 to a position such that the blade 28 will cut a buttonhole in register with the stitched pattern produced by the machine. WVith the die-securing screws, 40 loosened, the cutter-levers are then carefully closed and the punch 28 projected into the die, after which the screws 40 are tightened securely to hold the die in correct position. Should the free end of the punch-element become worn it may be readily removed from its carrier, ground off to renew the cutting edge and replaced in correct position. New punch anddie elements may be readily substituted for worn elements from time to time and may easily and quickly be re-set in correct cutting position- The lower cutter-lever is slotted at 43 below the die-element 36 to provide a passage- February 17 1920 and comprises the usual.

lower clamping plates 44 and upper clamping feet 45 carried at the forward ends of the usual clamping arms 46 which are closed upon the work in the usual manner by a turning I movement of the clamp-closing rock-shaft 47.

The lower clamp-plates 44 are mounted as usual on the cross slide-plate 48 which receives lateral motion from a lever 49 engaging the cam-groove 50 in the feed-wheel 51-. The cross slide-plate 48 is mounted at its forward end upon the cross-rod 52 carried by the forwardly extended arms 53 of the usual longitudinal slide-frame 54.

During the sewing operation, the longitudinal. slide-frame receives the usual feeding motion from a cam-groove 55 in the feed-wheel 51. The cam-groove 55 is entered by a stud 56 which projects downwardly from the lever 57 pivoted at 58 to the machine bed. The lever 57 carries an upwardly projecting stud 59 which enters a laterally extending recess in the longitudinal slide-frame; said recess being defined by the forwardly facing wall 60, Fig. 14, on the longitudinal slide-frame and-the rearwardly facing wall 61 formed on the coupling lever 62 which is pivoted by meansof the trunnion screws 63 to the longitudinalslideframe. e

Means substantially the same as shown in my Patent No. 1,330,156, are provided for temporarily uncoupling the longitudinal slide-frame from the feed-wheel and for rapidly shifting the slide-frame rearwardly the lateral pin 72 fixed tothe forward endportion of link-bar 73 which is formed with an L-shaped slot 74 and at its rearward end carries a lateral roll 75 which enters the cam-groove 7 6 in the outer face ofthe cam-disk 70. The link-bar 78, is supported at its rearward end by means of a block 77 on the cutter-shaft; the link-bar having a slot 7 8 embracing the block 7?.

The L-shaped slot 74 in the front end-portion of the link bar 73 is entered by the screw-pin 7 9 which is threaded into the upstanding ear 80 of a bracket 81 secured to the longitudinal slide-frame 54c. In the position of the parts shown in Fig. 15, the longitudinal slide-frame is coupled to the feedwheel through the lever 57 and studpins 56 and 59. The horizontal portion of the L- shaped slot '74 permits the longitudinal slide-frame to move forwardly and rearwardly during the sewing. lVhen the clutch 5 is operated to start the cutter-shaft 3 on its single rotation, the cam 69 acts through the lever 66 to tilt the coupling lever 62 to the position shown in Fig. 16 and also to lift the front end of the link-bar 7 3 suiiiciently to position the pin 79 in the vertical portion of the L-shaped slot 74. Further motion of the cutter-shaft causes the link-bar 73 to be drawn rearwardly, thus drawing the workholder rearwardly to cutting position. Preferably simultaneously with this movement thecutter levers will be advanced to cutting position. After the buttonhole has been .cut the work-holder is returned to stitching position and coupled to the feedwheel for the ensuing stitching operation.

While I have disclosed the invention as embodied in a buttonhole sewing machine of a particular type having a traveling buttonhole cutter, it is to be understood that it is immaterial to-the invention whether the buttonhole cutter is moved to the work, or the work is moved to the cutter.

Having thus set forth the nature of my invention, what I claim herein is 1. Buttonhole cutting mechanism for sewing machines comprising, a pivoted carrierlever, a punch-element carried by said lever and having the form of a thin blade curved edgewise concentrically with thepivot of said lever, and a hollow diaelementadapted to be entered by said punch-element in removing a narrow strip of material to form the buttonhole slit.

2. Buttonhole cutting mechanism for sewing machines comprising, a pivoted carrierlever, a punch-element carried by said lever and having the form of a thin blade curved edgewisethroughout its length concentrically with the pivot of said lever, and a hollow die-element adapted to be entered by said punch-element in removing a narrow strip of material to form the buttonhole slit.

3. Buttonholecutting mechanism forsewing machines comprising, a pivoted carrierlever, a punch-element carried by-said lever and having theform of a thin blade thickened along one edge to simulate, in cross-secee s-e0 tion, the shape of an eyelet-end buttonhole slit, said blade being curved edgewise concentrically with the pivot of said lever, with the thickened edge of said blade'nearer said pivot than the thin edge, and a hollow dieelement complementary to and adapted to be entered by said punch-element in removing a narrow strip of material to form the but tonhole slit.

in a buttonhole sewing machine, the 75 combination with stitch-forming mechanism including a reciprocating needle and a workholder with means for relatively moving them to sew around a buttonhole, of button hole cutting mechanism comprising a pivoted carrier-lever, a punch-element carried by said lever and having the form of a thin blade curved cdgewise concentrically with the pivot of said lever, a hollow die-element adapted to be entered by said punch-element in removing a narrow strip of material to form the buttonhole slit, and securing means permitting lateral adjustment of said punch and die-elements to register the buttonholeslit with the switched-pattern produced. by the machine.

5. In a buttonhole sewing machine, the combination with stitch-forming mechanism including a reciprocating needle and a workholder with means for relatively moving them to sew around a buttonhole, of buttonhole cutting mechanism comprising a pivoted carrierlever, a punch-element carried by said lever and having the form of a thin blade thickened along one edge to simulate, in cross-section, the shape of an eyelet-end buttonhole-slit, said blade being curved e-dgewise concentrically with the pivot of said lever, with the thickened edge of said blade. nearersaid pivot than the thin edge, a hollow die-element complementary to and adapted to be entered by said punch-element in removing a narrow strip of material to form the buttonhole slit, and securing means permitting lateral adjustment of said punch and die-elements to register the buttonhole-slit with the stitched pattern produced by the machine.

6. Buttonhole cutting mechanismfor sew.- ing machines comprising a pivoted carrier lever, a punch-element carried by said lever and having the form of a thin blade thickened along one edge to-simulate, in cross section, the shape of an eyeletrend buttonhole slit, said blade being curved edgewise I2 concentrically with the pivot for said lever, and securing means for the punch-element permitting endwise adjustment of thelatter on said lever in the arc of a circle having as a center the axis of the pivot for said lever.

7. Buttonhole cutting mechanism for sewing machines comprising a pivoted carrier lever, a punch element simulating in cross sectlonal shape the form of an eyelet-end buttonhole slit and curved edgewise concentrically with the axis of the pivot for said lever, a die-element complementary to said punch-element and adjusting means for the punchelement including opposed and grooved gripping walls curved concentrically with the axis of said carrier lever and permitting endwise adjustment of the punch-element in its curved path of operative movement.

8. Buttonhole cutting mechanism for sewing machines comprising, a pivoted carrierlever, a punch-element curved concentrically with the axis of the pivot for said carrier-lever, a split carrier having opposed grooves adapted to receive said curved punch-element, means for securing said punch-carrier to said lever, and a hollow die-element complementary to said punchelement.

9. Buttonhole cutting mechanism for sewing machines comprising, a pivoted carrierlever recessed at its forward end to provide a seat, a punch-element curved concentrically with the pivot of said carrier-lever, a split punch-carrier secured to said seat and having opposed faces formed with curved grooves adapted to receive and grip the punch-element, and a hollow die-element adapted to be entered by said punch-element.

10. Buttonhole cutting mechanism for sewing machines comprising, a pivoted carrier-lever, a punch-element of uniform cross-section throughout its length and curved concentrically with the pivot of said carrier-lever, a split carrier-block in which said punch-element is embedded, and means for detachablv securing said carrier-block to said carrier-lever.

11. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a work-holder, a buttonhole cutter, a feedwheel, means including a latch-lever pivoted to said Work-holder for disconnectibly connecting the work-holder to the feedwheel, the pivot of the latch-lever being transverse to the direction of movement imparted to the work-holder through said latch-lever by the feed-wheel, means acting upon said latch-lever to release the workholder from the feed-wheel, and means for shifting the Work-holder to and from buttonhole cutting position.

In testimony whereof, I have signed my name to this specification.

EDWARD B. ALLEN. 

